Gain gems from wars

what about awarding players gems for every star they gain for their clan. so the most you can gain per war is 6. but for example...if you attack someone that has 2 stars already on them...and you 3 star the base, you only 'gain' 1 star so you only get 1 gem for that attack instead of all 3. i think this would help promote war activity and get people to attack early in the war so they can get the most gems as possible. and it wouldnt be a huge amount of gems if you think about it...i mean you can get 6 gems from a mushroom right? so it wouldnt be too OP